1. Field of the Invention
The present invention relates to a hydrogen supplying apparatus and to a method for controlling a hydrogen supplying apparatus.
2. Description of the Related Art
In a conventional hydrogen supplying apparatus, such as proposed in Japanese Patent Application Publication No. 2004-111167 (JP-A-2004-111167), hydrogen that contains high-concentration odorizing agent is added to pure hydrogen released from a tank in response to the odorizing agent concentration in the hydrogen flowing in an odorized hydrogen circulation path, which includes the target of the hydrogen supply (for example, a fuel cell), to control the odorizing agent concentration in the hydrogen supplied to the target of the hydrogen supply and is supplied to the odorized hydrogen circulation path.
In the art described in the Japanese Patent Application Publication No. 2004-111167 (JP-A-2004-111167), an odorizing agent treated hydrogen tank that stores hydrogen into which is mixed a high-concentration odorizing agent is required. Because the odorizing agent treated hydrogen tank stores hydrogen and the odorizing agent, its size increases, leading to an increase in the size of the system. Considering this point, because if the odorizing agent treated hydrogen tank is made small, the amount of stored odorizing agent becomes less than if only the odorizing agent is stored, there is a possibility that the cycle of replenishing the tank with odorizing agent treated hydrogen (replacing the odorizing agent treated hydrogen tank) becomes short. Also, in the art of the Japanese Patent Application Publication No. 2004-111167 (JP-A-2004-111167), because the amount of odorizing agent treated hydrogen mixed with the pure hydrogen is not considered, there is a possibility of variations occurring in the odorizing agent concentration in the hydrogen supplied to the odorizing agent treated hydrogen circulation path.